<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<div  style="height: 300px;width: 300px;background-color: darkcyan;font-size: 20px;color: #ffffff;">
    这是a页面哦
</div>
</body>
</html>